Snubbing unit for inserting tubular members without a riser

Abstract

The snubbing unit inserts a tubular member into a well without a riser. The snubbing unit includes a set of stationary slips in a first base plate, a first set of traveling slips in a second base plate, a second set of traveling slips in a third base plate, and a plurality of hydraulic cylinders connecting the base plates. Each set of slips has an engaged position and a released position relative to the hydraulic cylinders. The base plates are cooperative with a pipe guide so that movement of the tubular member between the base plates corresponds to consistent support of the tubular member to preventing buckling. The snubbing unit increases safety and support for inserting into the well without a riser.

We claim: 
     
       1. A snubbing unit, comprising:
 a. a set of stationary slips disposed into a first base plate; 
 b. a first set of traveling slips disposed into a second base plate, the second base plate movable relative to the first base plate; 
 c. a second set of traveling slips disposed into a third base plate, the second base plate movable relative to the third base plate such that movement of the second base plate relative to the first base plate determines movement of the third base plate relative to the second base plate; and 
 d. a plurality of hydraulic cylinders connecting said first base plate to said second base plate and said second base plate to said third base plate, each set of slips comprising an engaged position and a released position relative to the hydraulic cylinders, each hydraulic cylinder of the plurality of hydraulic cylinders comprising an inner guide tube, a piston rod, and a piston cylinder, each hydraulic cylinder of the plurality of hydraulic cylinders being operable when actuated to move the second base plate relative to the first base plate and move the third base plate relative to the second base plate. 
 
     
     
       2. The snubbing unit, according to  claim 1 , wherein the inner guide tube is slidable into a respective piston cylinder according to position of said piston rod, each piston rod being attached to said first base plate, each respective piston cylinder being positioned beneath said first base plate. 
     
     
       3. The snubbing unit, according to  claim 1 , each inner guide tube of each hydraulic cylinder having a distal end attached to said third base plate and a proximal end engaged to a respective piston cylinder. 
     
     
       4. The snubbing unit, according to  claim 1 , wherein each inner guide tube is stationary relative to said first base plate, wherein at least one of said set of stationary slips, said first set of traveling slips, and said second set of traveling slips is in an engaged position. 
     
     
       5. The snubbing unit, according to  claim 1 , wherein each inner guide tube is stationary relative to said first base plate, said set of stationary slips being in an engaged position. 
     
     
       6. The snubbing unit, according to  claim 1 , wherein each inner guide tube is in motion relative to said first base plate, said set of stationary slips being in a released position, and wherein at least one of said first set of traveling slips and said second set of traveling slips is in an engaged position. 
     
     
       7. The snubbing unit, according to  claim 1 , wherein said second base plate is adjacent to said first base plate, and wherein each inner guide tube is in motion relative to said first base plate, said set of stationary slips being in a released position, said first set of traveling slips being in a released position, said second set of traveling slips being in an engaged position. 
     
     
       8. An assembly for inserting a tubular member, comprising:
 a. a snubbing unit, comprising a set of stationary slips disposed into a first base plate, a first set of traveling slips disposed into a second base plate, a second set of traveling slips disposed into a third base plate, and a plurality of hydraulic cylinders connecting said first base plate to said second base plate and said second base plate to said third base plate, each hydraulic cylinder of the plurality of hydraulic cylinders comprising an inner guide tube, a piston rod, and a piston cylinder, each of said hydraulic cylinders operative when actuated to move said second base plate relative to said first base plate and move said third base plate relative to said second base plate, wherein said movement of said second base plate to said first base plate determines said movement of said third base plate to said second base plate; 
 b. a tubular member inserting through said snubbing unit from said third base plate to said second base plate and said second base plate to first base plate, said tubular member being releasably engaged to said set of stationary slips, said tubular member being releasably engaged to said first set of traveling slips, said tubular member being releasably engaged to said second set of traveling slips; and 
 c. a pipe guide apparatus being set between said first base plate and said third base plate and through said second base plate and having a top end mounted to said third base plate and a bottom end mounted to said first base plate, said tubular member inserting through said pipe guide apparatus, 
 d. wherein each slips have an engaged position and a released position relative to said tubular member and said pipe guide apparatus. 
 
     
     
       9. The assembly, according to  claim 8 , wherein said pipe guide apparatus comprises:
 a. a lower slotted cylinder comprising a bottom base ring on a bottom base end at said bottom end and a plurality of finger extensions projecting upward from said bottom base ring to an extension tip end; and 
 b. an upper slotted cylinder comprising an upper base ring on a top base end at said top end and a plurality of complementary finger extensions projecting downward from said upper base ring to a complementary extension tip end, 
 c. wherein said lower slotted cylinder engages said upper slotted cylinder, said finger extensions sliding between said complementary finger extensions when said top base end moves toward said bottom base end, and 
 d. wherein the finger extensions maintain alignment of said tubular member, the complementary finger extensions maintaining alignment of said tubular member, both the finger extensions and the complementary finger extensions together maintaining alignment of said tubular member. 
 
     
     
       10. The assembly, according to  claim 9 , wherein said bottom base ring is mounted to said first base plate, and wherein said upper base ring is mounted to said third base plate. 
     
     
       11. The assembly, according to  claim 9 , wherein said bottom base ring is mounted to said first base plate, and wherein said upper base ring is mounted to said second base plate. 
     
     
       12. The assembly, according to  claim 9 , wherein said finger extensions extend through said upper base ring, wherein said bottom base ring is mounted to said first base plate, and wherein said upper base ring is mounted to said third base plate. 
     
     
       13. The assembly, according to  claim 9 , wherein said finger extensions extend through said upper base ring, wherein said bottom base ring is mounted to said first base plate, and wherein said upper base ring is mounted to said second base plate. 
     
     
       14. The assembly, according to  claim 8 , wherein said tubular member is stationary relative to said first base plate, said set of stationary slips being in an engaged position, and wherein at least one of said first set of traveling slips and said second set of traveling slips is in an engaged position. 
     
     
       15. The assembly, according to  claim 8 , wherein said tubular member is stationary relative to said first base plate, said set of stationary slips being in an engaged position, said first set of traveling slips being in a released position, and said second set of traveling slips being in a released position. 
     
     
       16. The assembly, according to  claim 8 , wherein said tubular member is in motion relative to said first base plate, said set of stationary slips being in a released position, said first set of traveling slips being in an engaged position, said second set of traveling slips being in an engaged position. 
     
     
       17. The assembly, according to  claim 8 , wherein said tubular member is in motion relative to said first base plate, said set of stationary slips being in a released position, and wherein at least one of said first set of traveling slips and said second set of traveling slips is in an engaged position. 
     
     
       18. The assembly, according to  claim 9 , wherein said upper base ring is mounted to said third base plate, wherein said second base plate is adjacent to said first base plate, and wherein said tubular member is in motion relative to said first base plate, said set of stationary slips being in a released position, said first set of traveling slips being in a released position, said second set of traveling slips being in an engaged position. 
     
     
       19. The assembly, according to  claim 8 , wherein each hydraulic cylinder comprises an inner guide tube, a piston rod, and a piston cylinder, each inner guide tube being slidable into a respective piston cylinder according to position of said piston rod, each piston rod being attached to said first base plate, each respective piston cylinder being positioned beneath said first base plate. 
     
     
       20. The assembly, according to  claim 8 , each inner guide tube having a distal end attached to said third base plate and a proximal end engaged to a respective piston cylinder.